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Heat pumps
Heat pumps · Error codes · Riello
L8Riello · NXHM (R32 monobloc)

L8 on a Riello NXHM: Speed difference >15 Hz protection between the front and the back clock

Short answer

On a Riello heat pump, L8 means: Speed difference >15 Hz protection between the front and the back clock. The manual does not say whether the heat pump stops. An engineer is needed to fix the cause.

Reviewed 23 September 2026 · 1 source

What it means

The manual says: Speed difference >15 Hz protection between the front and the back clock.

Likely causes:

  • As for L0 (inverter module checks).

Is it safe?

Does the heat pump stop?Not stated
Engineer needed?Yes

The manual does not say whether the heat pump stops.

What you can check

  • Read and note the exact code shown on the controller display.
  • Check the heat pump's breaker/isolator at the consumer unit is on.
  • Restart once via the controller (OFF then ON) as the manual allows; if the code returns, call an engineer.

What the engineer will check

  • As for L0 (inverter module checks).

Sources

A code explains what the controller detected, not a confirmed root cause.

Reviewed: 23 September 2026